Half of the polar ice cap is missing: Arctic sea ice hits a new record low

Extraordinary melting of sea ice in the Arctic this summer has shattered the all-time low sea ice extent record set in September 2007, and sea ice continues to decline far below what has ever been observed. The new sea ice record was set on August 26, a full three weeks before the usual end of the melting season, according to the National Snow and Ice Data Center. Every major scientific institution that tracks Arctic sea ice agrees that new records for low ice area, extent, and volume have been set. These organizations include the University of Washington Polar Science Center (a new record for low ice volume), the Nansen Environmental & Remote Sensing Center in Norway, and the University of Illinois Cryosphere Today. A comprehensive collection of sea ice graphs shows the full story. Satellite records of sea ice extent date back to 1979, though a 2011 study by Kinnard et al. shows that the Arctic hasn't seen a melt like this for at least 1,450 years (see a more detailed article on this over at skepticalscience.com.) The latest September 5, 2012 extent of 3.5 million square kilometers is approximately a 50% reduction in the area of Arctic covered by sea ice, compared to the average from 1979 - 2000. The ice continues to melt, and has not reached the low for this year yet.

Figure 2. Sea ice extent on September 5, 2012, showed that half of the polar ice cap was missing, compared to the average from 1979 - 2000. Image credit: National Snow and Ice Data Center.

Why the Arctic sea ice is importantArctic sea ice is an important component of the global climate system. The polar ice caps help to regulate global temperature by reflecting sunlight back into space. White snow and ice at the poles reflects sunlight, but dark ocean absorbs it. Replacing bright sea ice with dark ocean is a recipe for more and faster global warming. The Autumn air temperature over the Arctic has increased by 4 - 6°F in the past decade, and we could already be seeing the impacts of this warming in the mid-latitudes, by an increase in extreme weather events. Another non-trivial impact of the absence of sea ice is increased melting in Greenland. We already saw an unprecedented melting event in Greenland this year, and as warming continues, the likelihood of these events increase.

Huge storm pummels AlaskaA massive low pressure system with a central pressure of 970 mb swept through Alaska on Tuesday, generating hurricane-force wind gusts near Anchorage, Alaska that knocked out power to 55,000 homes. Mighty Alaskan storms like this are common in winter, but rare in summer and early fall. The National Weather Service in Anchorage said in their Wednesday forecast discussion that the forecast wind speeds from this storm were incredibly strong for this time of year--four to six standard anomalies above normal. A four-standard anomaly event occurs once every 43 years, and a five-standard anomaly event is a 1-in-4800 year event. However, a meteorologist I heard from who lives in the Anchorage area characterized the wind damage that actually occurred as a 1-in-10 year event. A few maximum wind gusts recorded on Tuesday during the storm:

The storm has weakened to a central pressure of 988 mb today, and is located just north of Alaska. The storm is predicted to bring strong winds of 25 - 35 mph and large waves to the edge of the record-thin and record-small Arctic ice cap, and may add to the unprecedented decline in Arctic sea ice being observed this summer.

Figure 5. An unusually strong storm formed off the coast of Alaska on August 5 and tracked into the center of the Arctic Ocean, where it slowly dissipated over the next several days. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite captured this natural-color mosaic image on Aug. 6, 2012. The center of the storm at that date was located in the middle of the Arctic Ocean. Image credit: NASA.

Arctic storms may be increasing due to climate changeThis week's Alaskan storm is the second unusually strong low pressure system to affect the Arctic in the past month. On August 4 - 8, a mighty storm with a central pressure of 963 mb raged through the Arctic, bringing strong winds that helped scatter and break up Arctic sea ice. According to a detailed post at NASA Earth Observatory, that storm was in the top 3 percent for strongest storms ever recorded north of 70 degrees latitude. A study of long-term Arctic cyclone trends authored by a team led by John Walsh and Xiangdong Zhang of the University of Alaska Fairbanks found that number and intensity of Arctic cyclones has increased during the second half of the twentieth century, particularly during the summer. Dr. Zhang explained that climate change has caused sea ice to retreat markedly in recent decades and has also warmed Arctic Ocean temperatures. Such changes may be providing more energy and moisture to support cyclone development and persistence. The strong storms of this week and a month ago would have had far less impact on the ice just a decade ago, when the sea ice was much thicker and more extensive.

A sea ice decline double-whammyThe monster Arctic storms like we've seen this year have sped up the rate of sea ice loss, but increased water temperatures and air temperatures due to human-caused global warming are the dominant reasons for the record melting of the Arctic sea ice. A July 2012 study by Day et al. found that the most influential of the possible natural influences on sea ice loss was the Atlantic Multi-decadal Oscillation (AMO). The AMO has two phases, negative (cold) and positive (warm), which impact Arctic sea ice. The negative phase tends to create sea surface temperatures in the far north Atlantic that are colder than average. In this study, the AMO only accounted for 5% - 31% of the observed September sea ice decline since 1979. The scientists concluded that given the lack of evidence that natural forces were controlling sea ice fluctuations, the majority of sea ice decline we've seen during the 1953 - 2010 period was due to human causes.

Joe Romm has a more in-depth look at the new Arctic sea ice record and what it means for the future over at climateprogess.org.

Up to 323,000 people could die if three earthquakes occur simultaneously along the Nankai Trough, killing about 70 percent of victims in subsequent tsunami, according to new predictions by two Cabinet Office panels.

The panels on Wednesday released predictions of damage that would be caused by a magnitude-9 Nankai Trough triple quake. This is the largest triple quake expected to occur in the trough--which stretches from off Shizuoka Prefecture down to Shikoku and Kyushu--with the so-called Tokai, Tonankai and Nankai earthquakes happening simultaneously.

The size of the predicted focal area is twice that of the magnitude-8.7 triple quake predicted by the government's Central Disaster Management Council in 2003.

One of the study panels was tasked with estimating the height of tsunami and the area of inundated regions, while the other was a working group assigned to predict damage that would be caused by the quake and tsunami. The working group determined a quick evacuation could reduce tsunami deaths by 80 percent, and called on the central and municipal governments concerned to secure evacuation facilities and routes.

The study panel in March released its predictions on maximum seismic intensity levels and the heights of tsunami. It improved the accuracy of its calculations for the latest predictions, while also expanding the information to include areas predicted to be inundated.

Meanwhile, the working group combined several potential tsunami patterns and kinds of tremors to predict possible damage based on different seasons and times of day when the quake could occur.

For the worst-case scenario in which 323,000 people could die, the working group made its prediction based on an assumption that the quake would occur at midnight during winter, when many people are expected to be home, and cause serious damage in the Tokai region.

The number of people who could perish in this scenario is 17 times greater than the figure in the Great East Japan Earthquake in March 11, 2011. About 18,800, including both dead and missing persons, were lost in that disaster.

The latest prediction of fatalities is 13 times higher than the predicted death toll of 25,000 from a previously expected triple quake, released by the government's Central Disaster Management Council in 2003.

According to the working group's predictions, 623,000 people could be injured and 311,000 people could require rescue.

In another scenario, about 32,000 people could die if the Nankai quake occurs at noon in the summertime, when many people are expected to be away from home, and causes serious damage in the Shikoku and Kyushu regions. This represents the case with the lowest death toll among the predictions.

Alternatively, if the triple quake occurs at 6 p.m. in wintertime, when many people use fires for things like cooking and heating, up to about 2.39 million buildings could collapse or burn down.

The working group also estimated the effects of disaster prevention measures.

For example, if 70 percent of people concerned started evacuating within 10 minutes after a midnight quake and took refuge in tsunami evacuation buildings, the tsunami death toll would drop by up to 80 percent.

As of 2008, the national average of buildings made earthquake-resistant was 80 percent. If the ratio of earthquake-resistant buildings were increased to 90 percent, the number of collapsed buildings could be reduced by about 40 percent.

The study panel predicted that up to 1,050 square kilometers of land would be inundated, 1.8 times more than the area flooded in the Great East Japan Earthquake and tsunami.

The predicted heights of tsunami do not differ much from the prediction released in March, with the highest reaching 34 meters in Kuroshio and Tosa-Shimizu, both in Kochi Prefecture.

The Cabinet Office will announce its predictions on economic damage, including the effects on electricity supply, water and sewage, and transportation, as early as this autumn. It will also develop countermeasures against a possible Nankai quake during winter.

Masaharu Nakagawa, state minister for disaster management, said at a press conference Wednesday that the government aims to create a special law by merging several existing laws related to the Tokai, Tonankai and Nankai earthquakes.

I stated that glacial ice melting from a land source would raise sea levels. Didn't you read that in my original post? The original question was about melting sea ice. I never stated that glacial ice melts wouldn't raise sea levels. The ice in Greenland is retained primarily in glaciers, so glacial melting will raise sea levels. We're both saying the same thing. I don't understand why you can't get that.

typical to take one sentence. i stated that if the ice over land melts

the next sentence after your quote is: There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt.

I stated that glacial ice melting from a land source would raise sea levels. Didn't you read that in my original post? The original question was about melting sea ice. I never stated that glacial ice melts wouldn't raise sea levels. The ice in Greenland is retained primarily in glaciers, so glacial melting will raise sea levels. We're both saying the same thing. I don't understand why you can't get that.

Quoting HurricaneHunterJoe:looking around about 8 billion for a double reactor set each producing 2 gigabites each start about 10 a year=80 billion which ya get from savings on defense and desalinization plants.............and more infrastructure ...why dont we have dams and piping to store flood waters and pipe it to locations in drought...work for a lot of construction workers...... business/gov doing something that will benefit all...... no more coal plants and then sell the coal to china for a good profit.....i don't know how much uranium/plutonium to run a pair of 2 gigabite reactors.............you would need another shuttle type program to send the nuclear waste into the sun or perhaps a better place.

Joe, I have no idea what a 2 gigabite reactor is. Sounds more like an old hard drive. :) The typical cost for a 1,000 megawatt plant is about $10-$17 billion, depending on location. It usually takes about eight years from intial permitting to start-up. We'd need over 500 plants that size to switch to completely nuclear, including reserve capacity. That's about $5 trillion bucks. Even for the government, that's not spare change., Capital costs are the biggest barrier to new nuke plant construction.

As far as dams to supply water to drought areas, he biggest problem is topography. Water flows downhill but not so good uphill. You'd first have to find a place for all the reservoirs and then you need a ton of pumping stations to move the water over hills, or uphill generally. Those take a lot of electricity, so you need more nuke plants...it's kind of a death spiral in cost. It would put a lot of people to work but we'd be broke when we're done.

As far as nuclear waste being launched to the sun, the concept would work. The only problem is little things like when the Challenger blew up. If it was carrying a load of spent fuel, there would be a lot of unhappy people back here on earth.

From your link:At the other end of the world, the North Pole, the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted sea levels would not be affecte­d.

This is exactly what I stated. What part of it don't you understand?

typical to take one sentence. i stated that if the ice over land melts

the next sentence after your quote is: There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt.

Ya know, that thing is behaving over water just like it did over land. We had our heaviest rain and convection when the low was still 200 miles north of us. I still haven't figured out how that could have happened, but it appears to still be happening. You'd think, at some point, that naked swirl just has to go poof...but Isaac's ghost still makes me nervous. :)

looking around about 8 billion for a double reactor set each producing 2 gigabites each start about 10 a year=80 billion which ya get from savings on defense and desalinization plants.............and more infrastructure ...why dont we have dams and piping to store flood waters and pipe it to locations in drought...work for a lot of construction workers...... business/gov doing something that will benefit all...... no more coal plants and then sell the coal to china for a good profit.....i don't know how much uranium/plutonium to run a pair of 2 gigabite reactors.............you would need another shuttle type program to send the nuclear waste into the sun or perhaps a better place.

Quoting GTcooliebai:Dennis thinks the front might clear the area by Sunday afternoon. What is your thoughts about that? I'm thinking a couple of less humid nights.

Assuming you're talking about Florida, the front/remnants of 90L won't clear the area by Sunday afternoon. The front will be dragging a pretty impressive pool of cooler air for this time in September. The front should stall somewhere over central Florida, allowing the pool of cooler air to remain over you for about two days. It should be somewhat cooler and much less humid. Up here in AL, I'll take the less hot and humd thing, since it's still 80 degrees right now in Montgomery, but I am a little concerned that this cool air may provide a focus for some severe thunderstorms Saturday afternoon, during the peak heating of the day. Our high Sunday is supposed to be 85 with a low of 61, which would be most welcome. I might be able to turn off the A/C for the first time since late April.

Hey I'm still talking tropics, next system to come off of Africa looks good for development. The models don't seem to be handling how quickly Leslie and Michael leaves the picture and how quickly the ridge builds in behind them. After that it will come down to how strong the Bermuda High will be as to how far west this system will go.

Quoting HurricaneHunterJoe:Hi Tom....had a flash flood up here last week about a mile from my house.....had like 2 feet of water and muck across Highway 79.

Hey Joe, that's pretty neat. Seems like we've had a pretty active monsoon season here in the Southwest...although the city of San Diego itself really hasn't gotten any rain at all from the monsoonal developments. We almost had rain on Wednesday when some low to mid level remnants of John came through.

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANELESLIE...LOCATED ABOUT 430 MILES SOUTH-SOUTHEAST OF BERMUDA...ANDON HURRICANE MICHAEL...LOCATED ABOUT 930 MILES WEST-SOUTHWESTOF THE AZORES.

1. A NEARLY STATIONARY AREA OF LOW PRESSURE LOCATED ABOUT 60 MILESSOUTHEAST OF THE MOUTH OF THE MISSISSIPPI RIVER IS PRODUCINGDISORGANIZED SHOWERS AND THUNDERSTORMS WELL TO THE SOUTHWEST OF THECENTER. ALTHOUGH ENVIRONMENTAL CONDITIONS ARE NOT EXPECTED TOBECOME SIGNIFICANTLY MORE FAVORABLE...THERE IS STILL SOME POTENTIALFOR DEVELOPMENT DURING THE NEXT COUPLE OF DAYS. THIS SYSTEM HAS AMEDIUM CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURINGTHE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THENEXT 48 HOURS.

Quoting HurricaneHunterJoe:Like I said bad at math. so if we are using 30,000 trillion watt hours per year in the usa,how many big reactors we need to take care of those needs?

As I wrote, 79% more capacity than we have now. It's hard to answer in terms of reactors, since they range from relatively small to monsterous. The largest single reactor in the USA is Palo Verde #3, in Arizona, that produces 1,317 MW's of electricity. It would take somewhere around 100 reactors this size to produce all the electric power in the USA. In addition to the gigantic costs involved, these large reactors need be located near a sizaable and dependable source of cooling water. That greatly limits where plants can be sited, not to mention the NIMBY syndrome when it comes to anything nuclear.

Quoting HurricaneHunterJoe:Math is not a good subject for me. Is it true that the biggest commercial nuclear reactor is only like 2MWh?

The largest nuke plant in the world in terms of power produced is the Kashiwazaki-Kariwa Nuclear Power Plant in Japan. It produces 33,317 GW-h (that's gigawatts, 1,000 megawatts) per year on average. The smallest power facility I ever worked with was an 8 MW-h hydro facility, located in the wilds of northern California, that had turbines well over 100 years old. If the entire plant went off-line, the guys in power control told me it would take them about an hour to even notice. :)